Float retention arrangement for humidification chamber

ABSTRACT

A float retention arrangement and related methods for a humidification chamber that includes at least one float that operates an inlet valve that controls a flow of water through a water inlet opening of the humidification chamber. A cover of the humidification chamber defines an interior space, at least one gas port and a float retention opening. A component forms at least a portion of a water supply conduit for supplying water from a water source to the water inlet opening. The component is insertable into the float retention opening and is positionable to contact and retain the at least one float in a non-use position. In some configurations, the component can be a water spike.

INCORPORATION BY REFERENCE

This application claims priority to U.S. Provisional Patent ApplicationNo. 61/873,777, filed Sep. 4, 2013, the entirety of which is herebyincorporated by reference herein and made a part of the presentdisclosure.

BACKGROUND Field

The present disclosure relates to humidifiers for respiratory supportsystems. More particularly, the present disclosure relates to a floatretention arrangement for a humidification chamber.

Description of Related Art

In a humidification chamber, one or more floats regulate the level ofwater flowing into the chamber by controlling a till valve. Floatretention devices are used to hold the float(s) in a desired positionpost-manufacture to prevent or reduce occurrence of impact damage andfatigue to the components of the float valve mechanism during transportand storage. The float valve mechanism comprises floats, lift arms,valve diaphragms, and float hinges. Damage to any component of the floatvalve mechanism could result in an uncontrolled water level within thechamber, which is undesirable. Typically, the float retention deviceholds the float in a position corresponding to an open position of thewater inlet valve.

Prior art float retention devices, or float retainers, are oftenassembled onto the gas inlet and outlet ports, typically duringmanufacture. The float retainer is intended to be removed and discardedby the user at the point-of-use. The float retainer can incorporate portcaps, which can provide a substantially airtight seal to inhibit orprevent ingress of foreign material into the inlet or outlet portsduring transport and storage.

As described above, typically, the water inlet valve is held open by thefloat retainer. Thus, the humidification chamber could overfill if thewater spike, which provides water to the water inlet valve, is insertedinto a water source before the float retainer is removed. In addition,the float retainer precludes factory pre-assembly of breathing tubes andadapters to the chamber because the float retainer obstructs the inletand outlet ports until removed by the end user at the point-of-use.

SUMMARY

The systems, methods and devices described herein have innovativeaspects, no single one of which is indispensable or solely responsiblefor their desirable attributes. Without limiting the scope of theclaims, some of the advantageous features will now be summarized.

In some configurations, a humidification chamber comprises a coverdefining an interior space. The cover comprises at least one gas port, awater inlet opening and a float retention opening. At least one floatoperates an inlet valve that controls a flow of water through the waterinlet opening. A water supply conduit has a first end and a second end.The first end is connected to the water inlet opening. An adapter isconnected to the second end of the water supply conduit and isconfigured, in use, to couple the water supply conduit to a source ofwater. The adapter is insertable into the float retention opening and ispositionable to contact and retain the at least one float in a non-useposition.

In some configurations, the adapter is a water spike.

In some configurations, the at least one float comprises a primary floatand a secondary float.

In some configurations, the at least one gas port comprises a gas inletport and a gas outlet port.

In some configurations, the water spike comprises a handle.

In some configurations, a tip of the water spike contacts the at leastone float.

In some configurations, when the adapter is positioned in the floatretention opening, the adapter does not obstruct the at least one gasport such that breathing tubes, adapters or other components can becoupled to the at least one gas port with the adapter positioned in thefloat retention opening.

In some configurations, a humidification chamber comprises a coverdefining an interior space. The cover comprises at least one gas port, awater inlet opening and a float retention opening. At least one floatoperates an inlet valve that controls a flow of water through the waterinlet opening. A component forms at least a portion of a water supplyconduit for supplying water from a water source to the water inletopening. The component is insertable into the float retention openingand is positionable to contact and retain the at least one float in anon-use position.

In some configurations, the at least one float comprises a primary floatand a secondary float.

In some configurations, the at least one gas port comprises a gas inletport and a gas outlet port.

In some configurations, a method of retaining a float of ahumidification chamber comprises inserting an adapter that is connectedto a free end of a water supply conduit through a float retentionopening in a cover of the humidification chamber until the adapter movesand retains the float in a non-use position, wherein an end of the watersupply conduit opposite the free end is coupled to a water inlet of thehumidification chamber.

In some configurations, a method of using a humidification chambercomprises removing an adapter that is connected to a free end of a watersupply conduit from a float retention opening in a cover of thehumidification chamber to release a float from a non-use position,wherein an end of the water supply conduit opposite the free end iscoupled to a water inlet of the humidification chamber.

BRIEF DESCRIPTION OF THE DRAWINGS

Throughout the drawings, reference numbers can be reused to indicategeneral correspondence between reference elements. The drawings areprovided to illustrate example embodiments described herein and are notintended to limit the scope of the disclosure.

FIG. 1 is a perspective view of a humidification chamber having a floatretention arrangement, which preferably comprises a water spike insertedinto the chamber to retain the float(s) in a non-use (e.g., storageand/or shipping) position.

FIG. 2 is a front view of the humidification chamber of FIG. 1 with thewater spike removed to illustrate an access opening through which thewater spike can be inserted.

FIG. 3 is a side view of the water spike separate from thehumidification chamber.

FIG. 4 is a sectional view of the humidification chamber of FIG. 1illustrating a dual valve arrangement and interaction between the waterspike, the cover of the chamber and the floats.

FIG. 5 is a perspective view of a humidification chamber having a floatretention arrangement, such as the arrangement of FIGS. 1-4,illustrating that breathing tubes can be assembled with the floatretention arrangement in use.

FIG. 6 is a perspective view of a humidification chamber having a floatretention arrangement, such as the arrangement of FIGS. 1-4, wherein thewater spike omits the finger loop.

FIG. 7 is a sectional view of a humidification chamber having a floatretention arrangement, such as the arrangement of FIGS. 1-4, wherein theaccess opening includes a cover or seal element.

DETAILED DESCRIPTION

In one or more embodiments of the present humidification chamber, acomponent of the humidification chamber is utilized as a float retainerin at least one mode of the humidification chamber, such as a storage orshipping mode, for example and without limitation. The componentpreferably is a component that has utility in connection with the use ofthe humidification chamber other than use as a float retainer. Forexample, in some configurations, the component used as a float retaineris or includes an adapter for connecting the humidification chamber to asource of water (e.g., a water spike). In at least some configurations,the water spike can be inserted through an access opening in the chambercover, wherein the access opening is separate from the gas inlet portand the gas outlet port. The access opening can be separate from thewater inlet. The humidification chamber can be of any suitablearrangement that includes one or more floats (or other movablecomponents) that are desirably held in a particular position (e.g., openor a non-use position) under certain circumstances (e.g., duringnon-use, such as shipping or storage). An example of a humidificationchamber is described below. Components or features of the humidificationchamber not discussed in detail herein can be of any suitableconstruction, such as the same as or similar to corresponding componentsor features of the humidification chambers disclosed in Applicant's PCTPublication No. WO2013/162386, entitled USABILITY FEATURES FORRESPIRATORY HUMIDIFICATION SYSTEM, and related U.S. priority applicationNos. 61/639,632 and 61/785,733, the entireties of which are herebyincorporated by reference herein. However, other suitable arrangementscan also be used.

With reference to FIGS. 1-4, the humidification chamber 100 generallycomprises a housing defining an internal space, an inlet port 102 and anoutlet port 104, each of which communicate with the internal space ofthe humidification chamber 100. In use, gases flow into thehumidification chamber 100 via the inlet port 102. The gases arehumidified within the humidification chamber 100 and flow out of thehumidification chamber 100 through the outlet port 104.

The humidification chamber 100 is configured to be installed on a heaterplate of an associated humidifier, such that a base 106 of thehumidification chamber 100 contacts the heater plate of the humidifier.The base 106 preferably comprises a metal with good thermalconductivity, such as aluminum or copper, for example and withoutlimitation. The humidification chamber 100 is further configured to holda volume of a liquid, such as water. In use, the liquid contacts thebase 106. The base 106 is heated by the heater plate, which causes atleast some of liquid in the humidification chamber 100 to evaporate.

A water reservoir, such as a water bag (not shown), supplies liquidwater to the humidification chamber 100 through a water inlet 108 inuse. As discussed, the humidification chamber 100 contains water in bothliquid and vapor phases as a result of heat energy supplied through theheat transfer base 106 by the heater plate of the associated humidifier.Liquid water enters the humidification chamber 100 through the waterinlet 108 and rises to a level dependent on the amount of water allowedto enter the humidification chamber 100 by a suitable controlarrangement, such as one or more valves.

In the illustrated arrangement, a dual valve arrangement 110 controlsthe entry of liquid water from the water reservoir or other water supplyinto the humidification chamber 100. The illustrated dual valvearrangement 110 comprises a primary valve arrangement 112 (“primaryvalve 112”) and a secondary valve arrangement 114 (“secondary valve114”). At least one of the primary valve 112 and the secondary valve 114is controlled by a float. In the illustrated arrangement, the primaryvalve 112 is controlled by a primary float 116, which can be at leastpartially constructed of an air or gas-filled, scaled or unsealedelement or other buoyant structure which is able to rise and fall withthe water level. In the illustrated arrangement, the primary float 116includes a vent 116 a that opens on an upper surface of the float 116 ata position above the normal water line. The vent 116 a connects theinterior of the primary float 116 with the air space within thehumidification chamber 100 to avoid or reduce volume changes of theprimary float 116 as a result of pressure or temperature changes withinthe humidification chamber 100.

Preferably, the secondary valve 114 is also controlled by a float, whichis referred to herein as a secondary float 117. The secondary float 117can be at least partially constructed of an air or gas-filled, sealed orunsealed element or other buoyant structure in a manner similar to theprimary float 116. In the illustrated arrangement, the secondary float117 does not include a vent. The larger volume compared to the primaryfloat 116 and the secondary, back-up functionality of the secondaryfloat 117 reduces or eliminates the advantages of a vent in thesecondary float 117. That is, the secondary float 117 generally operatesonly in the event of a malfunction of the primary float 116 to shut offthe supply of water to the humidification chamber 100. Thus, finecontrol of the secondary valve 117 is not necessarily required andchanges in buoyancy due to volume changes can be tolerated. However, insome arrangements, a vent could be provided.

In some configurations, one of the valves 110, 112 is not controlled bya float, but is operated by an alternative arrangement. For example, thesecondary valve 114 can be controlled by an alternative arrangement,such as a water level sensor and actuator arrangement, so that the usualsecondary float can be omitted to provide additional useful volumewithin the humidification chamber 100 or space for other components orarrangements. In such configurations, the float retention arrangementcan be modified accordingly from that illustrated herein.

The illustrated first or primary float 116 includes a couplingarrangement, such as a coupling arm 118, which is pivotally connected tosupport, such as a hinge bracket 120, for movement about an axis ofrotation of the primary float 116. The hinge bracket 120 can besupported by any suitable portion of the humidification chamber body.For example, an upper portion of the hinge bracket 120 can be coupled(e.g., fastened, snap-fit or bonded) to the water inlet 108 portion ofthe humidification chamber body and, if desired, a lower portion of thehinge bracket 120 can rest against a side surface of the humidificationchamber body. Thus, the primary float 116 rises and falls along with thewater level within the humidification chamber 100.

The primary float 116 actuates the primary valve 112. In particular, theprimary float 116 moves a push rod 124, which includes a first portionor lower end portion 128 pivotally coupled to the coupling arm 118 ofthe primary float 116 and a second portion or upper end portion 126. Theupper end portion 126 includes a valve body 130 that cooperates with afirst valve seat 132 of the dual valve arrangement 110. The valve body130 and first valve seat 132 form a portion of the first or primaryvalve 112. The valve body 130 can engage the first valve seat 132,directly or indirectly, to close the primary valve 112 and create atleast a substantial seal that inhibits or substantially prevents waterfrom entering the humidification chamber 100 through the primary valve112. The valve body 130 can also be disengaged from the first valve seat132 to open the primary valve 112 and permit entry of water into thehumidification chamber 100. The primary float 116, coupling arm 118,push rod 124 and first valve seat 132 are sized, proportioned, arrangedor otherwise configured to close the primary valve 112 once a desirablewater level within the humidification chamber 100 is reached and to openthe primary valve 112 when the actual water level falls below thedesirable water level thereby preferably maintaining the actual waterlevel at or near the desirable water level.

The secondary valve 114 operates in conjunction with the primary valve112 as a redundant or failsafe arrangement. Preferably, the primaryvalve 112 controls the entry of water into the humidification chamber100 under normal operating conditions. However, if the primary valve 112should malfunction or, for whatever reason, the water level should riseabove the desirable water level, the secondary valve 114 preferablycloses to inhibit or stop water from entering the humidification chamber100. The secondary valve 114 can also open when the water level fallsbelow the desirable water level to permit refill of water and continueduse of the humidifier 107.

The secondary valve 114 includes a movable valve body assembly 134 thatis movable between a closed position, in which a valve body element 136directly or indirectly engages a second valve seat 138 of the secondaryvalve 114 to inhibit or stop water from entering the humidificationchamber 100 through the secondary valve 114, and an open position, inwhich the valve body element 136 does not engage or close the secondvalve seat 138 of the secondary valve 114 so that water is permitted toenter the humidification chamber 100 through the secondary valve 114.

In the illustrated arrangement, the valve body assembly 134 is pivotallyconnected to the hinge bracket 120 for movement about an axis ofrotation. The illustrated valve body assembly 134 includes a base 142and a retainer cap 144 that support a push tube 146 therebetween. Thebase 142 is rotatably supported by the hinge bracket 120. The push tube146 defines or carries the valve body element 136. Preferably, the base142 defines a hemispherical portion and the push tube 146 defines acomplementary hemispherical portion that cooperate to form a ball-jointarrangement, which permits rotation of the push tube 146 relative to thebase 142 about two axes of rotation. Accordingly, a desirableorientation of the push tube 146 can be maintained throughout a range ofpivotal movement of the base 142. In some configurations, thehemispherical portions can be cylindrical such that the base 142 andpush tube 146 are movable about a single axis relative to one another.The retainer cap 144 can be secured to the base 142 by any suitablearrangement, such as a snap-fit arrangement, mechanical fasteners,adhesives or ultrasonic welding, for example and without limitation.Preferably, a space is provided between the retainer cap 144 and thepush tube 146 such that the retainer cap 144 inhibits separation of thepush tube 146 from the base 142, while allowing for relatively freemovement of the push tube 146 relative to the base 142.

In the illustrated arrangement, the push rod 124 is co-axial with thepush tube 146. The push rod 124 and push tube 146 are capable of movingfreely and independently of one another. The end of the push rod 124facing the water inlet 108 is tapered to a blunt point, which forms thevalve body 130. The valve body 130 of the push rod 124 and the valvebody element 136 of the push tube 146 can be covered by a valve sealelement, which can be a flexible sealing membrane. Such a valve sealelement can be configured to fit snugly over the rim of the push tube146, thus coupling the push tube 146 to the push rod 124 in a floatingconnection. Thus, in such a configuration, the valve seal element candirectly contact the first valve seat 132 and the second valve seat 138when the respective valve is in a closed position. In addition, thevalve seal element can prevent water from entering the humidificationchamber 100 through the water inlet 108 when the secondary valve 114 isclosed regardless of the position of the primary valve 112. The valveseal element can be made of material that is supple but strong, forexample, a medical grade silicone rubber material.

As described above, water is supplied to the humidification chamber 100from a water source by a supply tube arrangement comprising a supplytube 150. One end of the supply tube 150 is coupled to the water inlet108 and the other end of the supply tube 150 is coupled to an adapterfor coupling the supply tube 150 to a source of water. The adapter canbe in the form of a water spike 152, for example. Preferably, the waterspike 152 can also be used as a float retention device.

In at least some configurations, the water spike 152 can be insertedthrough an access opening 154 in the humidification chamber 100, such asin a chamber cover 156, for example. The access opening 154 can be inthe form of a slot and, in at least some configurations, can be locatedwithin a recess 158 defined by the cover 156. The recess 158 positionsthe water spike 152 in close proximity with the floats 116, 117, so thatthe water spike 152 does not need to be excessively long in order tocontact the floats 116, 117, while preserving the desired volume of thehumidification chamber 100. Accordingly, in at least someconfigurations, one or more dimensions (e.g., a width) of the recess 158are selected to accommodate the water spike 152 without substantialadditional space. For example, the width (or other dimension) of therecess 158 is preferably less than twice the width (or correspondingother dimension) of the water spike 152 and, in some configurations, isless than one and one-half times the width or less than one andone-quarter of the width.

In some embodiments, a cover or seal element 200 (FIG. 7) covers theaccess opening 154. In some embodiments, the seal element 200 comprisesa flexible silicone membrane 202. The flexible silicone membrane 202 canadditionally provide a protective sheath for the spike 152 to preventcontamination and damage to either or both of the spike 152 and float(s)116, 117. The cover or seal 200 could be another type of stretchablemembrane or other displaceable structure that stretches or moves toaccommodate insertion of the spike 152 through the access opening 154.In some embodiments, the cover or seal 200 maintains a physical barrieraround the spike 152 and between the spike 152 and the interior of thehumidification chamber 100. The membrane 202 (or displaceable structure)could include a reinforcing portion or member 204 that inhibits orprevents the spike 152 from puncturing the membrane 202 (or displaceablestructure). In some configurations, the cover or seal 200 could be aself-sealing membrane or valve (e.g., duckbill valve) that permits thespike 152 to pass through into the chamber 100 and that seals orsubstantially seals the access opening 154 when the spike 152 iswithdrawn. A separate member (e.g., a plug) could be provided to block,cover, or seal the access opening once the spike is removed. Theseparate member could be coupled to the chamber cover, such as near theaccess opening with a leash, lanyard, receptacle or other suitablearrangement.

The access opening 154 can be positioned above a certain water level ofthe chamber 100 (e.g., a maximum or normal level) such that blocking,covering, or sealing of the access opening 154 is not necessary. Thus,in some configurations, the access opening 154 can be open to theatmosphere. However, in any arrangement regardless of the location ofthe access opening 154, a cover, block, or seal may be provided ifdesired.

In some configurations, one or both of the inlet port 102 and the outletport 104 of the chamber 100 are not obstructed by the float retentionarrangement. Such an arrangement permits preassembly (such as duringmanufacture) or semi-permanent or permanent integration of breathingtubes 210, adapters 212 or other components to the inlet port 102 and/oroutlet port 104, as illustrated in FIG. 5.

In some configurations, the present float retention arrangementintrinsically inhibits or prevents water from being introduced into thechamber 100 while the float retention arrangement is in place. Onepurpose of the water spike 152 is to retain the float(s) 116, 117 in thenon-use position, but preferably the spike 152 is also the only path forwater to pass to the inlet valve 108 through the supply tube or conduit150 that extends between the inlet valve 108 and the water spike 152(FIG. 1). Thus, in the illustrated arrangement there is no way for waterto enter the chamber 100 through the inlet while the floats 116, 117 areretained in the non-use position and, thus, the valve arrangement 110 isheld open. Advantageously, with such an arrangement, water cannot beaccidentally introduced into the humidification chamber 100 via thenormal pathway of the supply tube 150 while the valve arrangement 110controlling the water inlet 108 is held open by a float retentionarrangement. Therefore, accidental overfilling of the humidificationchamber 100 can be avoided.

The water spike 152 can have any suitable structure to cooperate with asuitable water supply (e.g., water bag) and function as a floatretention device. For example, the water spike 152 can include a gripportion, such as a handle or finger loop 160, as shown in FIGS. 1-4.Alternatively, the water spike 152 can omit the handle or finger loop,as shown in the arrangement of FIG. 6. Such an arrangement can include abody of the water spike 152 that is sized and shaped or otherwiseconfigured to facilitate gripping and removal of the water spike 152.The water spike 152 comprises a passage or conduit 174 for water to movefrom a tip 172 of the water spike 152 to the supply tube 150.

The water spike 152 (or other retention component) can engage thefloat(s) 116, 117 in any suitable manner. In some configurations, thetip 172 of the water spike 152 contacts one of the floats (e.g., theprimary float). The water spike 152 can comprise a thin web portion 170that extends through the access opening 154 and has a lower end portionthat contacts one of the floats (e.g., the secondary float). FIG. 4illustrates one example of possible water spike 152 contact positionswith the floats 116, 117 (i.e., the retention locations). In someconfigurations, the water spike 152 contacts both floats 116, 117. Inthe illustrated arrangement, the water spike 152 contacts the frontportion of each float 116, 117, preferably at a location forward of anaxis of the gas inlet port 102 and/or outlet port 104, which can beforward of an entirety of the gas inlet port 102 and/or outlet port 104.

The primary float 116 can include a tab, arm 162 or other structure thatextends away from (e.g., forwardly from) a main body of the float 116and is contacted or otherwise engaged by the water spike 152. Similarly,the secondary float 117 can include a tab 164, arm or other structurethat extends from (e.g., forwardly from) a main body of the float 117that is contacted or otherwise engaged by the water spike 152. In theillustrated arrangement, the primary float 116 includes an elongate arm162 and the secondary float 117 includes a relatively small tab 164;however, other suitable arrangements can be used, including the waterspike 152 contacting a main body or buoyant portion of the floats 116,117. In the illustrated arrangement, the water spike 152 retains one orboth of the floats 116, 117 in a downward position (e.g., fully downwardcorresponding to a fully open position of the valves 112, 114.

The water spike 152 can define surfaces 176, 178 that contact and restupon the cover 156 with the water spike 152 in position to contact thefloats 116, 117. The surfaces 176, 178 can be defined by a main bodyportion of the water spike 152. The surfaces 176, 178 can be positionedforward and rearward of the tip 172. The surfaces 176, 178 can bevertically offset from one another. One of the surfaces 176 can beangled relative to an axis of the water spike 152. One of the surfaces178 can surround a portion of the web portion 170.

In the illustrated arrangement, the water spike 152 is located on a sideof the chamber 100 opposite the water inlet 108. Preferably, the waterinlet 108 is located on one side of a line extending through the axes ofthe gas inlet port 102 and outlet port 104 and the water spike 152 islocated on an opposite side of the line when engaged with the chamber100 as a float retention device. In such a position, the water spike 152can be diametrically opposed to the water inlet 108. A line passingthrough both the water inlet 108 and the water spike 152 can begenerally or substantially orthogonal to the line passing through theaxes of the gas inlet port 102 and outlet port 104.

In at least some configurations, the inlet and outlet ports 102, 104 arenot covered by the float retention device, thereby allowing factorypre-assembly or integration/permanent assembly of breathing tubes,adapters or other components to the humidification chamber. In at leastsome configurations, the float retention device intrinsically preventsthe flow of water into the chamber while floats are held down. In atleast some configurations, the float retention device reduces occurrenceof impact damage and fatigue to the components of the float valvemechanism during transport and/or storage. In some configurations, thefloat retention device provides an inherent protective sheath for thewater spike.

Unless the context clearly requires otherwise, throughout thedescription and the claims, the words “comprise”, “comprising”, and thelike, are to be construed in an inclusive sense as opposed to anexclusive or exhaustive sense, that is to say, in the sense of“including, but not limited to”.

Reference to any prior art in this specification is not, and should notbe taken as, an acknowledgement or any form of suggestion that thatprior art forms part of the common general knowledge in the field ofendeavour in any country in the world.

The invention may also be said broadly to consist in the parts, elementsand features referred to or indicated in the specification of theapplication, individually or collectively, in any or all combinations oftwo or more of said parts, elements or features.

Where, in the foregoing description reference has been made to integersor components having known equivalents thereof, those integers areherein incorporated as if individually set forth.

It should be noted that various changes and modifications to thepresently preferred embodiments described herein will be apparent tothose skilled in the art. Such changes and modifications may be madewithout departing from the spirit and scope of the invention and withoutdiminishing its attendant advantages. For instance, various componentsmay be repositioned as desired. It is therefore intended that suchchanges and modifications be included within the scope of the invention.Moreover, not all of the features, aspects and advantages arenecessarily required to practice the present invention. Accordingly, thescope of the present invention is intended to be defined only by theclaims that follow.

1.-12. (canceled)
 13. A circuit kit for a respiratory humidificationsystem comprising: a humidifier chamber having a gas inlet port, a gasoutlet port, a water inlet opening, and a float retention opening; aninspiratory breathing tube; a gas supply tube; and a water supplyconduit coupled between the water inlet opening and an adaptor, whereinthe kit is preassembled with the inspiratory breathing tube coupled tothe gas outlet port, the gas supply tube coupled to the gas inlet port,and the adapter inserted into the float retention opening.
 14. Thecircuit kit of claim 13, wherein the humidifier chamber comprises afirst float and a second float.
 15. The circuit kit of claim 14, whereinat least one of the first float and the second float operates at aninlet valve that controls a flow of water through the water inletopening.
 16. The circuit kit of claim 13, wherein the adapter is a waterspike.
 17. The circuit kit of claim 16, further comprising a coverconfigured to cover the float retention opening to provide a physicalbarrier between the water spike and an interior of the humidifierchamber.
 18. The circuit kit of claim 17, wherein the cover comprises amembrane or a valve.
 19. The circuit kit of claim 18, wherein the coveris self-sealing.
 20. The circuit kit of claim 17, wherein the covercomprises a stretchable membrane configured to stretch to accommodateinsertion of the water spike into the float retention opening.
 21. Thecircuit kit of claim 20, wherein the membrane comprises a reinforcedportion configured to prevent the water spike from puncturing themembrane.
 22. The circuit kit of claim 16, further comprising a separatemember configured to block the float retention opening when the waterspike is removed from the float retention opening.
 23. The circuit kitof claim 22, wherein the separate member is coupled to the humidifierchamber.
 24. The circuit kit of claim 14, wherein a portion of theadapter contacts at least one of the first float or the second floatwhen the adapter is positioned in the float retention opening.
 25. Thecircuit kit of claim 14, wherein at least one of the first float and thesecond float comprises buoyant structure configured to rise and fallwith a water level within the humidifier chamber.
 26. The circuit kit ofclaim 14, wherein at least one of the first float and the second floatis coupled to humidification chamber.
 27. The circuit kit of claim 26,wherein the first float is coupled to the humidification chamber with acoupling arm configured to support movement about an axis for rotationof the first float.
 28. The circuit kit of claim 14, wherein the firstfloat is coupled to the water inlet opening of the humidifier chamber.29. The circuit kit of claim 14, wherein the first float is configuredto operate an inlet valve that controls a flow of water through thewater inlet opening in use.
 30. The circuit kit of claim 13, wherein theinspiratory breathing tube, the gas supply tube, and the adapter arepermanently integrated to the humidifier chamber.